linux/drivers/media/dvb/frontends/lgdt330x.c
<<
>>
Prefs
   1/*
   2 *    Support for LGDT3302 and LGDT3303 - VSB/QAM
   3 *
   4 *    Copyright (C) 2005 Wilson Michaels <wilsonmichaels@earthlink.net>
   5 *
   6 *    This program is free software; you can redistribute it and/or modify
   7 *    it under the terms of the GNU General Public License as published by
   8 *    the Free Software Foundation; either version 2 of the License, or
   9 *    (at your option) any later version.
  10 *
  11 *    This program is distributed in the hope that it will be useful,
  12 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *    GNU General Public License for more details.
  15 *
  16 *    You should have received a copy of the GNU General Public License
  17 *    along with this program; if not, write to the Free Software
  18 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 *
  20 */
  21
  22/*
  23 *                      NOTES ABOUT THIS DRIVER
  24 *
  25 * This Linux driver supports:
  26 *   DViCO FusionHDTV 3 Gold-Q
  27 *   DViCO FusionHDTV 3 Gold-T
  28 *   DViCO FusionHDTV 5 Gold
  29 *   DViCO FusionHDTV 5 Lite
  30 *   DViCO FusionHDTV 5 USB Gold
  31 *   Air2PC/AirStar 2 ATSC 3rd generation (HD5000)
  32 *   pcHDTV HD5500
  33 *
  34 */
  35
  36#include <linux/kernel.h>
  37#include <linux/module.h>
  38#include <linux/init.h>
  39#include <linux/delay.h>
  40#include <linux/string.h>
  41#include <linux/slab.h>
  42#include <asm/byteorder.h>
  43
  44#include "dvb_frontend.h"
  45#include "dvb_math.h"
  46#include "lgdt330x_priv.h"
  47#include "lgdt330x.h"
  48
  49/* Use Equalizer Mean Squared Error instead of Phaser Tracker MSE */
  50/* #define USE_EQMSE */
  51
  52static int debug;
  53module_param(debug, int, 0644);
  54MODULE_PARM_DESC(debug,"Turn on/off lgdt330x frontend debugging (default:off).");
  55#define dprintk(args...) \
  56do { \
  57if (debug) printk(KERN_DEBUG "lgdt330x: " args); \
  58} while (0)
  59
  60struct lgdt330x_state
  61{
  62        struct i2c_adapter* i2c;
  63
  64        /* Configuration settings */
  65        const struct lgdt330x_config* config;
  66
  67        struct dvb_frontend frontend;
  68
  69        /* Demodulator private data */
  70        fe_modulation_t current_modulation;
  71        u32 snr; /* Result of last SNR calculation */
  72
  73        /* Tuner private data */
  74        u32 current_frequency;
  75};
  76
  77static int i2c_write_demod_bytes (struct lgdt330x_state* state,
  78                                  u8 *buf, /* data bytes to send */
  79                                  int len  /* number of bytes to send */ )
  80{
  81        struct i2c_msg msg =
  82                { .addr = state->config->demod_address,
  83                  .flags = 0,
  84                  .buf = buf,
  85                  .len = 2 };
  86        int i;
  87        int err;
  88
  89        for (i=0; i<len-1; i+=2){
  90                if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
  91                        printk(KERN_WARNING "lgdt330x: %s error (addr %02x <- %02x, err = %i)\n", __func__, msg.buf[0], msg.buf[1], err);
  92                        if (err < 0)
  93                                return err;
  94                        else
  95                                return -EREMOTEIO;
  96                }
  97                msg.buf += 2;
  98        }
  99        return 0;
 100}
 101
 102/*
 103 * This routine writes the register (reg) to the demod bus
 104 * then reads the data returned for (len) bytes.
 105 */
 106
 107static u8 i2c_read_demod_bytes (struct lgdt330x_state* state,
 108                               enum I2C_REG reg, u8* buf, int len)
 109{
 110        u8 wr [] = { reg };
 111        struct i2c_msg msg [] = {
 112                { .addr = state->config->demod_address,
 113                  .flags = 0, .buf = wr,  .len = 1 },
 114                { .addr = state->config->demod_address,
 115                  .flags = I2C_M_RD, .buf = buf, .len = len },
 116        };
 117        int ret;
 118        ret = i2c_transfer(state->i2c, msg, 2);
 119        if (ret != 2) {
 120                printk(KERN_WARNING "lgdt330x: %s: addr 0x%02x select 0x%02x error (ret == %i)\n", __func__, state->config->demod_address, reg, ret);
 121        } else {
 122                ret = 0;
 123        }
 124        return ret;
 125}
 126
 127/* Software reset */
 128static int lgdt3302_SwReset(struct lgdt330x_state* state)
 129{
 130        u8 ret;
 131        u8 reset[] = {
 132                IRQ_MASK,
 133                0x00 /* bit 6 is active low software reset
 134                      * bits 5-0 are 1 to mask interrupts */
 135        };
 136
 137        ret = i2c_write_demod_bytes(state,
 138                                    reset, sizeof(reset));
 139        if (ret == 0) {
 140
 141                /* force reset high (inactive) and unmask interrupts */
 142                reset[1] = 0x7f;
 143                ret = i2c_write_demod_bytes(state,
 144                                            reset, sizeof(reset));
 145        }
 146        return ret;
 147}
 148
 149static int lgdt3303_SwReset(struct lgdt330x_state* state)
 150{
 151        u8 ret;
 152        u8 reset[] = {
 153                0x02,
 154                0x00 /* bit 0 is active low software reset */
 155        };
 156
 157        ret = i2c_write_demod_bytes(state,
 158                                    reset, sizeof(reset));
 159        if (ret == 0) {
 160
 161                /* force reset high (inactive) */
 162                reset[1] = 0x01;
 163                ret = i2c_write_demod_bytes(state,
 164                                            reset, sizeof(reset));
 165        }
 166        return ret;
 167}
 168
 169static int lgdt330x_SwReset(struct lgdt330x_state* state)
 170{
 171        switch (state->config->demod_chip) {
 172        case LGDT3302:
 173                return lgdt3302_SwReset(state);
 174        case LGDT3303:
 175                return lgdt3303_SwReset(state);
 176        default:
 177                return -ENODEV;
 178        }
 179}
 180
 181static int lgdt330x_init(struct dvb_frontend* fe)
 182{
 183        /* Hardware reset is done using gpio[0] of cx23880x chip.
 184         * I'd like to do it here, but don't know how to find chip address.
 185         * cx88-cards.c arranges for the reset bit to be inactive (high).
 186         * Maybe there needs to be a callable function in cx88-core or
 187         * the caller of this function needs to do it. */
 188
 189        /*
 190         * Array of byte pairs <address, value>
 191         * to initialize each different chip
 192         */
 193        static u8 lgdt3302_init_data[] = {
 194                /* Use 50MHz parameter values from spec sheet since xtal is 50 */
 195                /* Change the value of NCOCTFV[25:0] of carrier
 196                   recovery center frequency register */
 197                VSB_CARRIER_FREQ0, 0x00,
 198                VSB_CARRIER_FREQ1, 0x87,
 199                VSB_CARRIER_FREQ2, 0x8e,
 200                VSB_CARRIER_FREQ3, 0x01,
 201                /* Change the TPCLK pin polarity
 202                   data is valid on falling clock */
 203                DEMUX_CONTROL, 0xfb,
 204                /* Change the value of IFBW[11:0] of
 205                   AGC IF/RF loop filter bandwidth register */
 206                AGC_RF_BANDWIDTH0, 0x40,
 207                AGC_RF_BANDWIDTH1, 0x93,
 208                AGC_RF_BANDWIDTH2, 0x00,
 209                /* Change the value of bit 6, 'nINAGCBY' and
 210                   'NSSEL[1:0] of ACG function control register 2 */
 211                AGC_FUNC_CTRL2, 0xc6,
 212                /* Change the value of bit 6 'RFFIX'
 213                   of AGC function control register 3 */
 214                AGC_FUNC_CTRL3, 0x40,
 215                /* Set the value of 'INLVTHD' register 0x2a/0x2c
 216                   to 0x7fe */
 217                AGC_DELAY0, 0x07,
 218                AGC_DELAY2, 0xfe,
 219                /* Change the value of IAGCBW[15:8]
 220                   of inner AGC loop filter bandwidth */
 221                AGC_LOOP_BANDWIDTH0, 0x08,
 222                AGC_LOOP_BANDWIDTH1, 0x9a
 223        };
 224
 225        static u8 lgdt3303_init_data[] = {
 226                0x4c, 0x14
 227        };
 228
 229        static u8 flip_1_lgdt3303_init_data[] = {
 230                0x4c, 0x14,
 231                0x87, 0xf3
 232        };
 233
 234        static u8 flip_2_lgdt3303_init_data[] = {
 235                0x4c, 0x14,
 236                0x87, 0xda
 237        };
 238
 239        struct lgdt330x_state* state = fe->demodulator_priv;
 240        char  *chip_name;
 241        int    err;
 242
 243        switch (state->config->demod_chip) {
 244        case LGDT3302:
 245                chip_name = "LGDT3302";
 246                err = i2c_write_demod_bytes(state, lgdt3302_init_data,
 247                                            sizeof(lgdt3302_init_data));
 248                break;
 249        case LGDT3303:
 250                chip_name = "LGDT3303";
 251                switch (state->config->clock_polarity_flip) {
 252                case 2:
 253                        err = i2c_write_demod_bytes(state,
 254                                        flip_2_lgdt3303_init_data,
 255                                        sizeof(flip_2_lgdt3303_init_data));
 256                        break;
 257                case 1:
 258                        err = i2c_write_demod_bytes(state,
 259                                        flip_1_lgdt3303_init_data,
 260                                        sizeof(flip_1_lgdt3303_init_data));
 261                        break;
 262                case 0:
 263                default:
 264                        err = i2c_write_demod_bytes(state, lgdt3303_init_data,
 265                                                    sizeof(lgdt3303_init_data));
 266                }
 267                break;
 268        default:
 269                chip_name = "undefined";
 270                printk (KERN_WARNING "Only LGDT3302 and LGDT3303 are supported chips.\n");
 271                err = -ENODEV;
 272        }
 273        dprintk("%s entered as %s\n", __func__, chip_name);
 274        if (err < 0)
 275                return err;
 276        return lgdt330x_SwReset(state);
 277}
 278
 279static int lgdt330x_read_ber(struct dvb_frontend* fe, u32* ber)
 280{
 281        *ber = 0; /* Not supplied by the demod chips */
 282        return 0;
 283}
 284
 285static int lgdt330x_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
 286{
 287        struct lgdt330x_state* state = fe->demodulator_priv;
 288        int err;
 289        u8 buf[2];
 290
 291        switch (state->config->demod_chip) {
 292        case LGDT3302:
 293                err = i2c_read_demod_bytes(state, LGDT3302_PACKET_ERR_COUNTER1,
 294                                           buf, sizeof(buf));
 295                break;
 296        case LGDT3303:
 297                err = i2c_read_demod_bytes(state, LGDT3303_PACKET_ERR_COUNTER1,
 298                                           buf, sizeof(buf));
 299                break;
 300        default:
 301                printk(KERN_WARNING
 302                       "Only LGDT3302 and LGDT3303 are supported chips.\n");
 303                err = -ENODEV;
 304        }
 305
 306        *ucblocks = (buf[0] << 8) | buf[1];
 307        return 0;
 308}
 309
 310static int lgdt330x_set_parameters(struct dvb_frontend* fe,
 311                                   struct dvb_frontend_parameters *param)
 312{
 313        /*
 314         * Array of byte pairs <address, value>
 315         * to initialize 8VSB for lgdt3303 chip 50 MHz IF
 316         */
 317        static u8 lgdt3303_8vsb_44_data[] = {
 318                0x04, 0x00,
 319                0x0d, 0x40,
 320                0x0e, 0x87,
 321                0x0f, 0x8e,
 322                0x10, 0x01,
 323                0x47, 0x8b };
 324
 325        /*
 326         * Array of byte pairs <address, value>
 327         * to initialize QAM for lgdt3303 chip
 328         */
 329        static u8 lgdt3303_qam_data[] = {
 330                0x04, 0x00,
 331                0x0d, 0x00,
 332                0x0e, 0x00,
 333                0x0f, 0x00,
 334                0x10, 0x00,
 335                0x51, 0x63,
 336                0x47, 0x66,
 337                0x48, 0x66,
 338                0x4d, 0x1a,
 339                0x49, 0x08,
 340                0x4a, 0x9b };
 341
 342        struct lgdt330x_state* state = fe->demodulator_priv;
 343
 344        static u8 top_ctrl_cfg[]   = { TOP_CONTROL, 0x03 };
 345
 346        int err;
 347        /* Change only if we are actually changing the modulation */
 348        if (state->current_modulation != param->u.vsb.modulation) {
 349                switch(param->u.vsb.modulation) {
 350                case VSB_8:
 351                        dprintk("%s: VSB_8 MODE\n", __func__);
 352
 353                        /* Select VSB mode */
 354                        top_ctrl_cfg[1] = 0x03;
 355
 356                        /* Select ANT connector if supported by card */
 357                        if (state->config->pll_rf_set)
 358                                state->config->pll_rf_set(fe, 1);
 359
 360                        if (state->config->demod_chip == LGDT3303) {
 361                                err = i2c_write_demod_bytes(state, lgdt3303_8vsb_44_data,
 362                                                            sizeof(lgdt3303_8vsb_44_data));
 363                        }
 364                        break;
 365
 366                case QAM_64:
 367                        dprintk("%s: QAM_64 MODE\n", __func__);
 368
 369                        /* Select QAM_64 mode */
 370                        top_ctrl_cfg[1] = 0x00;
 371
 372                        /* Select CABLE connector if supported by card */
 373                        if (state->config->pll_rf_set)
 374                                state->config->pll_rf_set(fe, 0);
 375
 376                        if (state->config->demod_chip == LGDT3303) {
 377                                err = i2c_write_demod_bytes(state, lgdt3303_qam_data,
 378                                                                                        sizeof(lgdt3303_qam_data));
 379                        }
 380                        break;
 381
 382                case QAM_256:
 383                        dprintk("%s: QAM_256 MODE\n", __func__);
 384
 385                        /* Select QAM_256 mode */
 386                        top_ctrl_cfg[1] = 0x01;
 387
 388                        /* Select CABLE connector if supported by card */
 389                        if (state->config->pll_rf_set)
 390                                state->config->pll_rf_set(fe, 0);
 391
 392                        if (state->config->demod_chip == LGDT3303) {
 393                                err = i2c_write_demod_bytes(state, lgdt3303_qam_data,
 394                                                                                        sizeof(lgdt3303_qam_data));
 395                        }
 396                        break;
 397                default:
 398                        printk(KERN_WARNING "lgdt330x: %s: Modulation type(%d) UNSUPPORTED\n", __func__, param->u.vsb.modulation);
 399                        return -1;
 400                }
 401                /*
 402                 * select serial or parallel MPEG harware interface
 403                 * Serial:   0x04 for LGDT3302 or 0x40 for LGDT3303
 404                 * Parallel: 0x00
 405                 */
 406                top_ctrl_cfg[1] |= state->config->serial_mpeg;
 407
 408                /* Select the requested mode */
 409                i2c_write_demod_bytes(state, top_ctrl_cfg,
 410                                      sizeof(top_ctrl_cfg));
 411                if (state->config->set_ts_params)
 412                        state->config->set_ts_params(fe, 0);
 413                state->current_modulation = param->u.vsb.modulation;
 414        }
 415
 416        /* Tune to the specified frequency */
 417        if (fe->ops.tuner_ops.set_params) {
 418                fe->ops.tuner_ops.set_params(fe, param);
 419                if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
 420        }
 421
 422        /* Keep track of the new frequency */
 423        /* FIXME this is the wrong way to do this...           */
 424        /* The tuner is shared with the video4linux analog API */
 425        state->current_frequency = param->frequency;
 426
 427        lgdt330x_SwReset(state);
 428        return 0;
 429}
 430
 431static int lgdt330x_get_frontend(struct dvb_frontend* fe,
 432                                 struct dvb_frontend_parameters* param)
 433{
 434        struct lgdt330x_state *state = fe->demodulator_priv;
 435        param->frequency = state->current_frequency;
 436        return 0;
 437}
 438
 439static int lgdt3302_read_status(struct dvb_frontend* fe, fe_status_t* status)
 440{
 441        struct lgdt330x_state* state = fe->demodulator_priv;
 442        u8 buf[3];
 443
 444        *status = 0; /* Reset status result */
 445
 446        /* AGC status register */
 447        i2c_read_demod_bytes(state, AGC_STATUS, buf, 1);
 448        dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, buf[0]);
 449        if ((buf[0] & 0x0c) == 0x8){
 450                /* Test signal does not exist flag */
 451                /* as well as the AGC lock flag.   */
 452                *status |= FE_HAS_SIGNAL;
 453        }
 454
 455        /*
 456         * You must set the Mask bits to 1 in the IRQ_MASK in order
 457         * to see that status bit in the IRQ_STATUS register.
 458         * This is done in SwReset();
 459         */
 460        /* signal status */
 461        i2c_read_demod_bytes(state, TOP_CONTROL, buf, sizeof(buf));
 462        dprintk("%s: TOP_CONTROL = 0x%02x, IRO_MASK = 0x%02x, IRQ_STATUS = 0x%02x\n", __func__, buf[0], buf[1], buf[2]);
 463
 464
 465        /* sync status */
 466        if ((buf[2] & 0x03) == 0x01) {
 467                *status |= FE_HAS_SYNC;
 468        }
 469
 470        /* FEC error status */
 471        if ((buf[2] & 0x0c) == 0x08) {
 472                *status |= FE_HAS_LOCK;
 473                *status |= FE_HAS_VITERBI;
 474        }
 475
 476        /* Carrier Recovery Lock Status Register */
 477        i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
 478        dprintk("%s: CARRIER_LOCK = 0x%02x\n", __func__, buf[0]);
 479        switch (state->current_modulation) {
 480        case QAM_256:
 481        case QAM_64:
 482                /* Need to undestand why there are 3 lock levels here */
 483                if ((buf[0] & 0x07) == 0x07)
 484                        *status |= FE_HAS_CARRIER;
 485                break;
 486        case VSB_8:
 487                if ((buf[0] & 0x80) == 0x80)
 488                        *status |= FE_HAS_CARRIER;
 489                break;
 490        default:
 491                printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
 492        }
 493
 494        return 0;
 495}
 496
 497static int lgdt3303_read_status(struct dvb_frontend* fe, fe_status_t* status)
 498{
 499        struct lgdt330x_state* state = fe->demodulator_priv;
 500        int err;
 501        u8 buf[3];
 502
 503        *status = 0; /* Reset status result */
 504
 505        /* lgdt3303 AGC status register */
 506        err = i2c_read_demod_bytes(state, 0x58, buf, 1);
 507        if (err < 0)
 508                return err;
 509
 510        dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, buf[0]);
 511        if ((buf[0] & 0x21) == 0x01){
 512                /* Test input signal does not exist flag */
 513                /* as well as the AGC lock flag.   */
 514                *status |= FE_HAS_SIGNAL;
 515        }
 516
 517        /* Carrier Recovery Lock Status Register */
 518        i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
 519        dprintk("%s: CARRIER_LOCK = 0x%02x\n", __func__, buf[0]);
 520        switch (state->current_modulation) {
 521        case QAM_256:
 522        case QAM_64:
 523                /* Need to undestand why there are 3 lock levels here */
 524                if ((buf[0] & 0x07) == 0x07)
 525                        *status |= FE_HAS_CARRIER;
 526                else
 527                        break;
 528                i2c_read_demod_bytes(state, 0x8a, buf, 1);
 529                if ((buf[0] & 0x04) == 0x04)
 530                        *status |= FE_HAS_SYNC;
 531                if ((buf[0] & 0x01) == 0x01)
 532                        *status |= FE_HAS_LOCK;
 533                if ((buf[0] & 0x08) == 0x08)
 534                        *status |= FE_HAS_VITERBI;
 535                break;
 536        case VSB_8:
 537                if ((buf[0] & 0x80) == 0x80)
 538                        *status |= FE_HAS_CARRIER;
 539                else
 540                        break;
 541                i2c_read_demod_bytes(state, 0x38, buf, 1);
 542                if ((buf[0] & 0x02) == 0x00)
 543                        *status |= FE_HAS_SYNC;
 544                if ((buf[0] & 0x01) == 0x01) {
 545                        *status |= FE_HAS_LOCK;
 546                        *status |= FE_HAS_VITERBI;
 547                }
 548                break;
 549        default:
 550                printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
 551        }
 552        return 0;
 553}
 554
 555/* Calculate SNR estimation (scaled by 2^24)
 556
 557   8-VSB SNR equations from LGDT3302 and LGDT3303 datasheets, QAM
 558   equations from LGDT3303 datasheet.  VSB is the same between the '02
 559   and '03, so maybe QAM is too?  Perhaps someone with a newer datasheet
 560   that has QAM information could verify?
 561
 562   For 8-VSB: (two ways, take your pick)
 563   LGDT3302:
 564     SNR_EQ = 10 * log10(25 * 24^2 / EQ_MSE)
 565   LGDT3303:
 566     SNR_EQ = 10 * log10(25 * 32^2 / EQ_MSE)
 567   LGDT3302 & LGDT3303:
 568     SNR_PT = 10 * log10(25 * 32^2 / PT_MSE)  (we use this one)
 569   For 64-QAM:
 570     SNR    = 10 * log10( 688128   / MSEQAM)
 571   For 256-QAM:
 572     SNR    = 10 * log10( 696320   / MSEQAM)
 573
 574   We re-write the snr equation as:
 575     SNR * 2^24 = 10*(c - intlog10(MSE))
 576   Where for 256-QAM, c = log10(696320) * 2^24, and so on. */
 577
 578static u32 calculate_snr(u32 mse, u32 c)
 579{
 580        if (mse == 0) /* No signal */
 581                return 0;
 582
 583        mse = intlog10(mse);
 584        if (mse > c) {
 585                /* Negative SNR, which is possible, but realisticly the
 586                demod will lose lock before the signal gets this bad.  The
 587                API only allows for unsigned values, so just return 0 */
 588                return 0;
 589        }
 590        return 10*(c - mse);
 591}
 592
 593static int lgdt3302_read_snr(struct dvb_frontend* fe, u16* snr)
 594{
 595        struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
 596        u8 buf[5];      /* read data buffer */
 597        u32 noise;      /* noise value */
 598        u32 c;          /* per-modulation SNR calculation constant */
 599
 600        switch(state->current_modulation) {
 601        case VSB_8:
 602                i2c_read_demod_bytes(state, LGDT3302_EQPH_ERR0, buf, 5);
 603#ifdef USE_EQMSE
 604                /* Use Equalizer Mean-Square Error Register */
 605                /* SNR for ranges from -15.61 to +41.58 */
 606                noise = ((buf[0] & 7) << 16) | (buf[1] << 8) | buf[2];
 607                c = 69765745; /* log10(25*24^2)*2^24 */
 608#else
 609                /* Use Phase Tracker Mean-Square Error Register */
 610                /* SNR for ranges from -13.11 to +44.08 */
 611                noise = ((buf[0] & 7<<3) << 13) | (buf[3] << 8) | buf[4];
 612                c = 73957994; /* log10(25*32^2)*2^24 */
 613#endif
 614                break;
 615        case QAM_64:
 616        case QAM_256:
 617                i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
 618                noise = ((buf[0] & 3) << 8) | buf[1];
 619                c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
 620                /* log10(688128)*2^24 and log10(696320)*2^24 */
 621                break;
 622        default:
 623                printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
 624                       __func__);
 625                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
 626        }
 627
 628        state->snr = calculate_snr(noise, c);
 629        *snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */
 630
 631        dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __func__, noise,
 632                state->snr >> 24, (((state->snr>>8) & 0xffff) * 100) >> 16);
 633
 634        return 0;
 635}
 636
 637static int lgdt3303_read_snr(struct dvb_frontend* fe, u16* snr)
 638{
 639        struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
 640        u8 buf[5];      /* read data buffer */
 641        u32 noise;      /* noise value */
 642        u32 c;          /* per-modulation SNR calculation constant */
 643
 644        switch(state->current_modulation) {
 645        case VSB_8:
 646                i2c_read_demod_bytes(state, LGDT3303_EQPH_ERR0, buf, 5);
 647#ifdef USE_EQMSE
 648                /* Use Equalizer Mean-Square Error Register */
 649                /* SNR for ranges from -16.12 to +44.08 */
 650                noise = ((buf[0] & 0x78) << 13) | (buf[1] << 8) | buf[2];
 651                c = 73957994; /* log10(25*32^2)*2^24 */
 652#else
 653                /* Use Phase Tracker Mean-Square Error Register */
 654                /* SNR for ranges from -13.11 to +44.08 */
 655                noise = ((buf[0] & 7) << 16) | (buf[3] << 8) | buf[4];
 656                c = 73957994; /* log10(25*32^2)*2^24 */
 657#endif
 658                break;
 659        case QAM_64:
 660        case QAM_256:
 661                i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
 662                noise = (buf[0] << 8) | buf[1];
 663                c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
 664                /* log10(688128)*2^24 and log10(696320)*2^24 */
 665                break;
 666        default:
 667                printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
 668                       __func__);
 669                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
 670        }
 671
 672        state->snr = calculate_snr(noise, c);
 673        *snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */
 674
 675        dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __func__, noise,
 676                state->snr >> 24, (((state->snr >> 8) & 0xffff) * 100) >> 16);
 677
 678        return 0;
 679}
 680
 681static int lgdt330x_read_signal_strength(struct dvb_frontend* fe, u16* strength)
 682{
 683        /* Calculate Strength from SNR up to 35dB */
 684        /* Even though the SNR can go higher than 35dB, there is some comfort */
 685        /* factor in having a range of strong signals that can show at 100%   */
 686        struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
 687        u16 snr;
 688        int ret;
 689
 690        ret = fe->ops.read_snr(fe, &snr);
 691        if (ret != 0)
 692                return ret;
 693        /* Rather than use the 8.8 value snr, use state->snr which is 8.24 */
 694        /* scale the range 0 - 35*2^24 into 0 - 65535 */
 695        if (state->snr >= 8960 * 0x10000)
 696                *strength = 0xffff;
 697        else
 698                *strength = state->snr / 8960;
 699
 700        return 0;
 701}
 702
 703static int lgdt330x_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fe_tune_settings)
 704{
 705        /* I have no idea about this - it may not be needed */
 706        fe_tune_settings->min_delay_ms = 500;
 707        fe_tune_settings->step_size = 0;
 708        fe_tune_settings->max_drift = 0;
 709        return 0;
 710}
 711
 712static void lgdt330x_release(struct dvb_frontend* fe)
 713{
 714        struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
 715        kfree(state);
 716}
 717
 718static struct dvb_frontend_ops lgdt3302_ops;
 719static struct dvb_frontend_ops lgdt3303_ops;
 720
 721struct dvb_frontend* lgdt330x_attach(const struct lgdt330x_config* config,
 722                                     struct i2c_adapter* i2c)
 723{
 724        struct lgdt330x_state* state = NULL;
 725        u8 buf[1];
 726
 727        /* Allocate memory for the internal state */
 728        state = kzalloc(sizeof(struct lgdt330x_state), GFP_KERNEL);
 729        if (state == NULL)
 730                goto error;
 731
 732        /* Setup the state */
 733        state->config = config;
 734        state->i2c = i2c;
 735
 736        /* Create dvb_frontend */
 737        switch (config->demod_chip) {
 738        case LGDT3302:
 739                memcpy(&state->frontend.ops, &lgdt3302_ops, sizeof(struct dvb_frontend_ops));
 740                break;
 741        case LGDT3303:
 742                memcpy(&state->frontend.ops, &lgdt3303_ops, sizeof(struct dvb_frontend_ops));
 743                break;
 744        default:
 745                goto error;
 746        }
 747        state->frontend.demodulator_priv = state;
 748
 749        /* Verify communication with demod chip */
 750        if (i2c_read_demod_bytes(state, 2, buf, 1))
 751                goto error;
 752
 753        state->current_frequency = -1;
 754        state->current_modulation = -1;
 755
 756        return &state->frontend;
 757
 758error:
 759        kfree(state);
 760        dprintk("%s: ERROR\n",__func__);
 761        return NULL;
 762}
 763
 764static struct dvb_frontend_ops lgdt3302_ops = {
 765        .info = {
 766                .name= "LG Electronics LGDT3302 VSB/QAM Frontend",
 767                .type = FE_ATSC,
 768                .frequency_min= 54000000,
 769                .frequency_max= 858000000,
 770                .frequency_stepsize= 62500,
 771                .symbol_rate_min    = 5056941,  /* QAM 64 */
 772                .symbol_rate_max    = 10762000, /* VSB 8  */
 773                .caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
 774        },
 775        .init                 = lgdt330x_init,
 776        .set_frontend         = lgdt330x_set_parameters,
 777        .get_frontend         = lgdt330x_get_frontend,
 778        .get_tune_settings    = lgdt330x_get_tune_settings,
 779        .read_status          = lgdt3302_read_status,
 780        .read_ber             = lgdt330x_read_ber,
 781        .read_signal_strength = lgdt330x_read_signal_strength,
 782        .read_snr             = lgdt3302_read_snr,
 783        .read_ucblocks        = lgdt330x_read_ucblocks,
 784        .release              = lgdt330x_release,
 785};
 786
 787static struct dvb_frontend_ops lgdt3303_ops = {
 788        .info = {
 789                .name= "LG Electronics LGDT3303 VSB/QAM Frontend",
 790                .type = FE_ATSC,
 791                .frequency_min= 54000000,
 792                .frequency_max= 858000000,
 793                .frequency_stepsize= 62500,
 794                .symbol_rate_min    = 5056941,  /* QAM 64 */
 795                .symbol_rate_max    = 10762000, /* VSB 8  */
 796                .caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
 797        },
 798        .init                 = lgdt330x_init,
 799        .set_frontend         = lgdt330x_set_parameters,
 800        .get_frontend         = lgdt330x_get_frontend,
 801        .get_tune_settings    = lgdt330x_get_tune_settings,
 802        .read_status          = lgdt3303_read_status,
 803        .read_ber             = lgdt330x_read_ber,
 804        .read_signal_strength = lgdt330x_read_signal_strength,
 805        .read_snr             = lgdt3303_read_snr,
 806        .read_ucblocks        = lgdt330x_read_ucblocks,
 807        .release              = lgdt330x_release,
 808};
 809
 810MODULE_DESCRIPTION("LGDT330X (ATSC 8VSB & ITU-T J.83 AnnexB 64/256 QAM) Demodulator Driver");
 811MODULE_AUTHOR("Wilson Michaels");
 812MODULE_LICENSE("GPL");
 813
 814EXPORT_SYMBOL(lgdt330x_attach);
 815
 816/*
 817 * Local variables:
 818 * c-basic-offset: 8
 819 * End:
 820 */
 821